Change speed transmission



Filed Dec. 28, 1940 3 Sheets-Sheet 1 G. "r. RANDOL 2,348,753 CHANGESPEED TRANSMISSIQN May. 16, 944

Filed Dad. 28, 1940 s Sheets-Sheet 2 GLENN 77* RANDOL} WWW flrra RIVEKa)- w W M G. T. RANDOL CHANGE SPEED wmusmssxdk Filed Dec. 28, 1940 May16, 1944. I

s Sheets-Sheet s fireman Patented May 16, 1944 -UNITED STATES PATENTOFFICE CHANGE SPEED TRANSMISSION Glenn T. Randol, St. Louis, Mo.,assignor of forty per cent to William M. Liddon, Nashville, Tenn.

Application December 28, 1940, Serial No. 372,047

11 Claims.

My invention relates to change speed transmissions and. moreparticularly to improved means for causing different gear ratios to beoperative. I

One of the objects of my invention is to produce a change speedtransmission having embodied therein improved clutch means and operatingmeans therefor for causing a gear ratio to be operative without injuryto the parts regardless of the speed of the vehicle.

Another object of my invention is to produce a combined positive clutchmeans and synchronizing means therefor for quietly and smoothlyconnecting. two rotatable elements together which can be caused to befirst operable and then inoperable by a member movable in either direction between two positions.

Still another object of my invention is to provide an improved positiveclutch means of the type embodying radially movable elements withassociated synchronizing means for connecting two rotative elementstogether.

A further object of my invention is to produce an improved changespeedtransmission in which the different forward and reverse gear ratioscan be obtained by a single movable member movable in oppositedirections from a central or neutral position.

Yet another object of my invention is to produce a change speedtransmission of the kind above referred to which is so constructed thatit can be controlled by a single shifting lever movable in a singleplane and in such a manner that the conventional H-slot shiftingarrangement can beretained without the necessity of complicated linkageconstruction between the shifting lever and the gearing and also be welladapted for use on motor vehicles as now on the market and which lendsitself to ready installation'in place of conventional equipment.

Other objects of my invention will become apparent from the followingdescription taken in connection with the accompanying drawings in whichFigure 1 is a partial sectional side view of a change speed transmissionembodying my invention, the parts being in neutral position; Figure 2 isa perspective view showing the shifting handle. and the manner in whichit is associated with the steering column and wheel; Figure 3 is asectional view taken on the line 3-3 of Figure 2; Figure 4 is a partialsectional top view of the change speed transmission with parts shown inhigh speed position; Figure 5 is a rear end view of the change speedtransmission; Figures'6; 7, '8 and 9 are sectional views taken on thelines 6-6, 1-1, 8-8 and 9-9 of Figure 1, showing the positive clutch andsynchronizing means thereforin neutral positions Figures l0 and 11 aresectional views taken on the lines Iii-40 and l lll of Figure 4, showingthe parts in operative high speed position; Figures 12 and 13 aresectional views similar to Figures 3 and 9 but showing the parts inoperative second speed position; Figure 14 isa perspective view of thetransmission driven shaft and the struc: ture carried thereby; Figure 15is a perspective view of the rotatable shifting member positioned in thedriven shaft; Figure 16 is another view of the rotatable shifting membershowing how certain parts are associated therewith; Figure 17 is a viewshowing the rail in the transmission casing upon which is slidable thesingle shifting fork; and Figure 18 is an enlarged View of one end ofthe synchronizer operating plungers and associated parts.

I have illustrated the transmission embodying my invention as beingassociated with an automobile but it is to be understood that it maybeused wherever a change speed transmission is desirable. In Figure 1 theengine I is connected to the drive shaft 2 of the change speedtransmission through the usual clutch (not shown) actuated by clutchpedal 3 and, positioned in the clutch housing 3'. To this clutch housingis secured the casing 4 of the change speed transmission. The drivenshaft 5 of the transmission is connected in the usual manner throughdifferential gearing to the wheels of the vehicle. This driven shaft isof hollow construction and extends into the transmission housing to apoint adjacent the drive shaft 2 where it is piloted inthe gear 6integral with the driving shaft 2. The gear 6 is in constant mesh with agear I of a cluster. of gears rotatably mounted on a countershaft 3having bearings in the housing and positioned parallel to the axiallyaligned drive and driven shafts. In addition to gear 1, the cluster ofgears also consists'of a second speed gear 9, a low speed gear l0 and areverse gear ii, the latter being in constant mesh'with an idler gear l2mounted on a stub shaft l3.

As best shown in Figure 14. the rear portion of the driven shaft 5 isprovided with external splines l t upon which is slidably mounted acombined low and reverse gear for continuous rotation with the drivenshaft. The splined portion of the driven shaft is also provided withopposed axially extending slots l6 and I! which receive, respectively,-pins i8 and I9 carried by gear 15, said pins being of such length as toproject slightly within the hollow portion of the driven shaft.

The forward end portion of the driven shaft ahead of the splines is ofsmooth construction and extends into an integral annular flange 2|] ongear 6. Between gear 6 and the splines is a second speed gear 2|rotatably mounted on the smooth portion of the driven shaft andconstantly meshing with gear 9 on the counter shaft. This gear 2| has aforwardly extending annular flange 22 which abuts the flange 26 of gear6. The flange 26 is provided with a plurality of recesses 23 on itsinner surface (see Figures 6 and 10) and flange 2| has similar recesses24 on its inner surface (see Figures 8 and 12).

Within hollow portion of the driven shaft is a clutch actuator shaft 25(Figures 15 and 16) which is capable of relative rotation only withrespect to said driven shaft. The forward end of this actuator has areduced portion which is piloted in a bearing 21 positioned in drivingshaft 2. The rear portion of the clutch actuator shaft is of cylindricalform and its surface is provided with two grooves 28 and 29, the formerreceiving the end of pin I8 and the latter the end of pin l9, previouslyreferred to. The groove 28 has straight portions and 3| on oppositesides of the shaft which are interconnected by a curved portion 32.Similarly, the groove 29 has straight portions 33 and 34 on oppositesides of the shaft which are interconnected by acurved portion 35. Thestraight portions 30 and 33 are at one end of the cylindrical portion ofthe shaft and the straight portions 3| and 34 are at the opposite ends.this construction it is seen that by moving gear l5 forward from itscentral or neutral position, as shown in Figure 1, the clutch actuatingshaft 25 can be rotated approximately 60 degrees in a clockwisedirection (Figure 14) relative to the driven shaft and if said gear ismoved rearwardly, shaft 25 can be rotated approximately 60 degrees in acounterclockwise direction relative to the driven shaft.

The forward end of the clutch actuating shaft 25 is formed with threeribs 36 spaced 120 degrees apart and between these ribs and the portion26 is a collar 31 shrunk onto the shaft, said collar being of a diameterequal to that of the cylindrical portion 25. This collar and the pilotedportion 26 support the forward end of the driven shaft. Extendingthrough the collar and the clutch actuating shaft is a square hole 38 inwhich is positioned plungers 39 and 46 having interposed therebetween aspring 4|. These plungers, under certain conditions, are adapted toengage with synchronizing shoes 42 carried by the forward end of thedriven shaft and cause them to frictionally engage with a ring 43secured to the inner surface of gear 6. The shoes and ring are made ofbronzeor some equivalent material. The forward end of the driven shaftalso carries three rollers 44 positioned in three slots 45 in the shaftspaced 120 degrees apart. These rollers are normally biased by a splitspring ring 46 in order to project into the hollow part of the drivenshaft where they can be engaged by the ribs 36 when the clutch actuatingshaft is rotated in a counterclockwise direction, as indicated by thearrow in Figures 6 and 10. The ring 46 lies within a groove 41 in flange26. When the clutch actuating shaft 25 is rotated to move the rollersoutwardly, the spring will expand and each roller will project up abovethe surface of the driven shaft and engagewith a recess 23 in saidflange to thereby connect gear 6 to the driven shaft so that power canbe transmitted directly from the drive shaft 2 to driven shaft 5.

The clutch actuating shaft 25 at a point just rearwardly of the ribs 36is provided with a second square hole 48 in which is positioned plungers49 and 56 having interposed therebetween a spring 5|. These plungers areadapted under certain conditions to cooperate with synchronizing shoes52 carried by driven shaft 5 and lying beneath gear 2|. A cooperatingfriction ring 53 is secured to gear 2|. The driven shaft just forward ofthe synchronizing shoes 52 carries three rollers 54 lying in slots 55spaced degrees apart in the driven shaft. These rollers are normallyheld in their inner position by a spring ring 46' where they projectinto the hollow portion of the driven shaft. In these positions therollers can be engaged by ribs 36 when clutch actuating shaft 25 isrotated in a clockwise direction (Figures 8 and 12) and be forcedoutwardly and into a recess 24 in flange 22 of gear 2| and thus connectsaid gear to the driven shaft. The spring ring lies in a groove 56 insaid flange 22. It is to be noted that the rollers 54 are staggered withrespect to rollers 44 associated with gear 6, this staggering relationbeing such that when the clutch actuating shaft 25 is in its neutralposition where all the rollers are held inwardly, the ribs on the clutchactuating shaft lie on one side of rollers 44 and on opposite sides ofrollers 54.

As best shown in Figure 18 wherein is disclosed an enlarged view of oneof the plungers, namely, plunger 49, and the related structure (theother plungers have the same construction) said plunger is provided witha rounded nose 51 and the edges 58 and 59 adjacent the inwardlyprojecting portion 60 of the synchronizing shoes are all rounded inorder to facilitate the disengagement of said plunger from the shoe whenthe clutch actuating shaft is rotated to such a position to bring theplunger from a position beneath the shoe to a position engaging theinner surface of the driven shaft. In the inoperative or neutralposition of the clutch actuating shaft all the plungers will be inengagement with the inner surface of the driven shaft and out ofengagement with the synchronizing shoes which they are adapted toactuate. This condition is shown in Figures 7 and 9 which is theinoperative or neutral position of the clutch actuating shaft. Theplungers are so related to each other that when the shaft is turned in acounter-clockwise direction, plungers 39 and 4|] will become operativeto position the synchronizing shoes outwardly and plungers 49 and 56will remain inoperative, since they continue to engage with the innersurface of the driven shaft. When the clutch actuating shaft is turnedin the opposite direction, plungers 49 and 56 will become operative toposition the synchronizing shoes 52 outwardly and plungers 39 and 46will remain inoperative. The synchronizing shoes will become operativebefore ribs 36 actuate the rollers since the ribs in their neutralposition are spaced slightly away from the rollers and do not engagesaid rollers until the corresponding synchronizer shoes are operatedwhen shaft 25 is rotated.

The means for moving gear l5 and rotating the clutch actuating shaft 25comprises a shifting fork 6| having a cylindrical portion 62 slidablymounted on a rod 63 carried on the side of the casing adjacent theclosure-plate 64. This rod, as shown in Figure 17, is provided with arecess 65 for cooperation with a detent 66 carried by the cylindricalportion 62 (see Figure 1). This detent, when in recess 65, determinesthe neutral position of the change speed transmission. The rod 63 oneach side of the recess 65 is formed with inclined surfaces 61 and 68and at the ends of these surfaces are shoulders 69 and ill against whichthe detent 66 is adapted to abut and thus determine the low and reversepositions of the transmission which are the extreme positions that gearI5 can be shifted in opposite directions from its neutral position.

The cylindrical portion 62 is also provided with a lug H which isreceived in the forked end' of an arm 12 secured to a stub shaft l3mounted in a bearing 14 of the cover plate and extending to the exteriorof the housing. The outer end of shaft 13 has secured thereto anotherlever 15 for rotating said shaft and lever 12 to move the shifting forkin opposite directions. Connected to 1ever 15 is a rod 16 which extendsforwardly and upwardly to where it is connected to an arm 11 secured toa shaft 18. This shaft 18 is mounted on the steering column 19 of theautomobile and extends parallel to the column. The lower end of theshaft has bearing in a bracket 80 secured to the lower portion of thesteering column and the upper end has bearing in a bracket 8| secured tothe upper portion of the steering column just beneath the steering wheel82.

The bracket 8| has a plate portion 83 in which is cut an H-slot 84.Beneath plate 83 and secured to shaft 18 is a cylindrical extension 85which receives a shifting handle 86 havin a projection 81 extendingthrough a slot 88 in the cylindrical portion and cooperating with theH-slot in the plate, said extension and H-slot cooperating to limit therotative movement of the handle to that required to shift the parts toobtain different speed ratios and also to provide definite positions forthe different operative positions of the transmission. The handle 86 isbiased outwardly by a spring 89 whereby the projection 81' will normallylie in the portion of the H-slot designated by the letters S and H andindicating the second and high speed positions, respectively, of thetransmission. These legs of the H-slot are shorter than th other legsdesignated by the letters L and R and corresponding to the low andreverse speeds of the transmission. Thus when projection 81 is in theportion of the H-slot corresponding to the second and high speedpositions, handle 86 is capable, of rotating shaft 13 through a smallerangle than when the projection is in the low and reverse portion of theH-slot. In order to put projection 8! in alignment with the low andreverse portions of the H-slot the handle need only be pushed axiallyinwardly by a finger of the operator when the pin coincides with thecross-over portion of the H-slot, said position corresponding to theneutral position of the change speed gearing as designated by the letterN on plate 83 (shown in Figure 2).

In the operation of my improved change speed transmission and thecontrol means, therefor, the neutral or inoperative position of theparts are as shown in Figure 1. Under these conditions the handle 86will be in such position that projection 81 will lie in the center ofthe S and H slots and in the position marked N. The sliding gear 15 ofthe change speed gearing will be centrally located on the splinedportion of the driven shaft and half-way between the lowspeedcountershaftgear l0 and reverse idler gear [2. The

recess: 65; of 'thesupportingrail 63..

If it is desired to place the transmission ln low speed, the main clutchcontrolled by the clutch pedal 3 is disengaged and handle 86 movedaxially toward the steering column to place projection 81 in alignmentwith the legs of the slot marked L and R. The handle is then pulleddownwardly so that the projection 81 will move to the end of the slotmarked L. The swinging of the handle downwardly in the plane of thesteering wheel will cause rotation of the shaft 78 and by means of therod 16 and lever and 12 cause the shifting fork 6| to be moved forwardlyor to the left, as shown in Figures 1 and hand to a position where gearI5 engages gear [0 on the countershaft to thereby connect thecountershaft to the driven shaft through said gears. Since the drivingshaft 2 is continuously connected by gears B and I to said countershaft,power can then be transmitted from driving shaft 2 to driven shaft 5 andthen to the wheelsof the vehicle when the main clutch is engaged.

As gear i5 is moved forwardly, pins l8 and I9 carried thereby andextending into grooves 28 and 29 will cause relative rotation of theclutch actuating shaft 25 in a clockwise direction, as viewed in Figure14. Because of the curved portions 32 and 35 of the grooves, therotation of the clutch actuating shaft will take place prior toengagement of gear l5 with gear l0 and the extent of this rotation willbe approximately 60 degrees. When gear l5 begins to engage gear Hi,there will be no rotation of shaft 25 due to the straight portions 30and 33 of the grooves. The rotation of the shaft 25 will first causeplungers 39 and iil (see Figures 7 and 11) to be moved to a positionwhere they can act on the synchronizing shoes 42 and thus force theseshoes outwardly into frictional engagement with the ring 43 carried bygear 8. If the vehicle is stationary, as will be the case if the vehicleis to be started from a stopped position, the driving shaft 2 and thedriven shaft 5 will both be stationary due to the fact that the mainclutch is disconnected from the engine. Therefore, no synchronizingaction will take place. The rotation of the clutch actuating shaft 25'to cause plungers 39 and 40 to act on the synchronizing shoes will besuch as to bring ribs 36 into'engagement with rollers M. Continuedrotation of the clutch actuating shaft will now cause rollers 44 to beshoved radially outwardly and into a recess 33 to thereby connect thedriving shaft to the driven shaft. When this connection takes place,gear It has reachedthe point indicated in Figure 4. This is high gearposition of the parts. As the gear is moved farther forward to engagegear It, the clutch actuating shaft will continue, to rotate in aclockwise direction, as seen in Figure 1%, or a counter-clockwisedirection as viewed in Figures 6 and 10. The ribs thus beyond therollers will permit these rollers to become disengaged from recesses 23under the action of the spring ring 46. The driven shaft will then bedisconnected from the driving shaft and as this takes place, gear l5will reach the position where it begins to engage with gear I0. Theclutch actuating shaft will no longer be rotated as the gears arebrought into full engagement due to the fact that pins l8 and I9 are nowin the straight portions 36 and 33 of the grooves.

If the transmission is in low speed position and it is desired to placeit in second speed position, the main clutch is disengaged and then thegear shifting handle is brought back to the cross slot of the H-slot andthe projection 81 allowed to" become aligned with the S leg OftheH--SIOt.

This will result in gear l5 being disengaged from the countershaft gearI and moved back to its neutral position. As soon as gear l becomesdisengaged from gear ID, pins l3 and I!) will cause the clutch actuatingshaft 25 to be'rotated in a counter-clockwise direction (Figure 14)thereby actuating the synchronizing shoes 42, engaging rollers 44 withrecesses 23, and then permitting their disengagement therefrom as aresult of continued rotation of said shaft. Because the synchronizeraction becomes operative before the rollers are moved outwardly by ribs36, there will beno difficulty in engaging the rollers, notwithstandingthat the driven shaft and the driving shaft may be rotating at differentspeeds when gears l5 and ID are disengaged. The synchronizing action issufficient to bring the driving and driven shafts to approximately equalspeeds at the time that the rollers are moved outwardly to engage therecesses 23.

After gear l5 has been brought back to its central position by themovement of the handle 86, the handle is then moved upwardly in a planeparallel to the plane of the steering wheel so that the projection 81goes to the end of the portion of the slot marked S. This will causegear I5 to move rearwardly or to the right, as viewed in Figures 1 and4. The pins, by means of grooves 28 and 29, will continue to rotate theclutch actuating shaft in a counter-clockwise direction as viewed inFigure 14, the extent of relative rotation being approximately 60degrees. This rotation of the shaft will move it from the position shownin Figures 8 and 9 to the position shown in Figures 12 and 13. The firstpart of the rotation will cause the plungers 49 and 50 to assume aposition where they can apply pressure to the synchronizing shoes 52.After this occurs, the ribs 36 will then engage the rollers 54 and forcethem outwardly into a recess 24 and thus cause second speed to beoperative when the main clutch is engaged. The engagement of the syn.-chronizing shoes with gear 2| will cause this gear to rotate withsubstantially the same speed as the driven shaft and when the rollersare forced outwardly, they will easily engage their recesses and thuspermit the rollers to engage smoothly.

- If it'is desired to place the transmission in high speed position, themain clutch is disengaged and then handle 8% is pulled downwardly sothat the projection 55% moved to the end of the slot marked H as shownin dotted lines in Figure 2. This will now cause gear 5 to be moved fromthe position where second speed is engaged to the position where highspeed is engaged. The high speed position of the levers T5 and T2employed moving gear 55 is shown in dotted lines in Figure l. Themovement of this gear will, by means of pins 58 and !9, cause relativerotation of the clutch engaging shaft through an angle of approximately120 degrees in a clockwise direction (Figure 14). The ribs 36 will thusbe moved from beneath the rollers 54 permitting their disengagement andthen moved into the position shown in Figure wherein rollers 44 will bemoved out into the recesses 23 and connect the driving an driven shaftstogether for direct drive when the main clutch is engaged. Prior to themovement of these rollers M. outwardly, plunger-s 39 and 59 will becomeoperative to move the synchronizing shoes 42 outwardly and cause thedriving shaft to be brought into substantial synchronous speed with thedriven shaft whereby said rollers can be easily engaged as alreadydescribed. The

high speed position of the parts is shown in Figures 4, .10 and 11'. 7

If reverse speed is desired at any time, the main clutch is disengagedand then the gear shifting handle 86 is first moved axially and thenupwardlyso that the projection B'I'is at the end of the slot marked R.This will cause gear l5v to be moved rearwardly to engage the idler gear12. During this movement the clutch .engaging'shaft 25 will be rotatedin a counter?- clockwise direction (Figure 14) by means of the pins I8and I9 so as to cause first the operation of the synchronizing frictionshoes 52, the engagement of the rollers 54 with their recesses, and thenpermit their disengagement, all prior to the engagement of the gear ISwith the idler gear l2. Since reverse gear is generally selected whenthe automobile is at a standstill, the synchronizing'friction shoes 52will not perform any work as the gear 2| and driven shaft 5 arestationary.

In the operation of the transmission just described, it is seen that inorder to obtain low speed ratio it is necessary to cause engagement anddisengagement of the high speed ratio and to obtain reverse gear ratioit is necessary to cause engagement and disengagement of the secondspeed ratio. This, however, is not a disadvantage since it is very easyto pass through" the second and high speed ratios due to the fact thatthe synchronizing means employed with each set of clutch rollers isoperative in both directions of rotation of the clutch actuating shaft.In other words, the synchronizing means permits synchronization beforeclutch engagement when the clutch actuating shaft is rotated in onedirection to cause clutch engagement and then disengagement and alsopermits synchronization before clutch engagement when said shaft isrotated in the reverse direction. The arrangement also has manyadvantages in normal operation of an automobile since the second andhigh speed gear ratios are employed to a greater extent than the othergear ratios, low speed gear being used only in starting the vehicle froma standstill or in going up a heavy grade. To obtain either second orhigh, it is only necessary to shift the shifting handle 86 back andforth in a plane parallel to the steering wheel. When the handle ismoved upwardly, the clutch engagingshaft is rotated to engage the secondspeed gear after first causing said gear, by means of the synchronizingmeans, to be brought to substantially the same speed as the drivenshaft. When the handle is moved downwardly, the clutch engaging shaft isrotated in the oppo'-- site direction to cause the driving shaft to 'be'directly connected to the driven shaft. The

projection 81 on the gear shifting handle is normally positioned inalignment with the S and H slots and, therefore, it is not necessary toaxially move the gear shifting handle at any time except when it isdesired to place the transmission either in low or reverse speed.' Thearrangement also permits a simplified connection betwee the gearshifting handle and the gear box as all shifting takes place by a backand forth movement, there being no necessity for a cross-over as ispresent standard practice. I

The change speed transmission is very' compact in arrangement andpermits easy selection of the different speeds. Any speed can beselected and engaged at any time. The clutch engaging shaft operates theclutch rollers'only by a rotative movement, there, being no necessityder either second or high speed ratio operative or inoperative.

Being aware of the possibility of modifications in the particularstructure herein described without departing from the fundamentalprinciples of my invention, I do not intend that {its scope be limitedpended claims.

Having fully described my invention, what I claim as new and desire tosecure by Letters Pat ent of the United States is:

except as set forth by the an- 1. In a transmission mechanism, a diiving member, a driven member, one of said members being provided with arecess. a radially movable clutch element carried by the other of saidmembers and adapted to engage the recess of the first named member tolock said members together, an actuating member mounted on the membercarrying the clutch element for relative rotation thereto on the sameaxis and provided with means to radially move the clutch element intothe recess when rotated relatively to the clutch carrying member, meansfor frictionally connecting the driving and driven members, and meansoperable by a rotation of the actuating member prior to the movement ofthe radially movable clutch element for operating said fr ctionalconnection.

2. In a transmission mechanism, a driving member, a driven member, oneof said members being rotatable around the other member and providedwith a recess, a clutch element carried by the other of said members andadapted tobe moved radially to engage the recess of the first namedmember to lock said members together, an actuating member mounted in themember carrying the clutch element and fixed against relativelongitudinal movement but rotatable relative thereto on the same axis toradially move the clutch element into the recess, means including amovable member carried by said other memher for frictionally connectingthe driving and driven members, and means operable by the rotatableactuating member for operating said movable member of the frictionalconnection to produce a synchronizing action prior to the movement ofthe clutch element radially.

3. In a transmission, a rotatable hollow shaft, a member rotatablethereon and provided with recesses adjacent the surface of the shaft, acircular clutch element carried in an opening in the Wall of the shaftbeneath the member, free to rotate therein and capable of being movedradi ally outwardly to engage with a recess in the member, a rotatableactuating element positioned in the hollow shaft and fixed againstrelative longitudinal movement, said element carrying a part forengaging the clutch element to force it outwardly, and means shifta-bleaxially of the shaft for rotating said actuating element.

4. In a transmission, a rotatable hollow shaft,

a member rotatable thereon and provided with recesses adjacent thesurface of the shaft, a circular clutch element carried in an opening inthe wall of the shaft beneath the member, free to rotate therein aboutits own axis and capable of being moved. radially outwardly to engagewith a recess in the member, a rotatable actuating element positioned inthe hollow shaft and fixed against relative longitudinal movement, saidelement carrying a part for enaging the clutch element to force itoutwardly, a friction-member carried by the shaft and movable outwardlyto engage the rotatable member, means carried by the rotatable actuatingelement for operating the friction member prior to movement of theclutch element outwardly when said rotatable element is rotated, andmeans shiftable axially of the shaft for rotating said actuatingelement.

5. In a transmission, a rotatable hollow shaft, a member rotatablethereon and provided with a recess adjacent the surface of the shaft, acircular clutch element carried in an opening in the wall of the shaftbeneath the member, free to rotate thereon about its own axis andcapable of being moved radially outwardly to engage a recess in themember, a rotatable actuating element positioned in the hollow shaft andfixed against relative longitudinal movement, said element carrying apart for engaging the clutch element to force it outwardly, said partbeing capable of passing beneath said clutch element from an inoperativeposition on one side thereof to an inoperative position on the otherside thereof as the element is rotated, and means for rotating saidrotatable actuating element in opposite directions.

6. In a transmission, a rotatable hollow shaft. a member rotatablethereon and provided with a recess adjacent the surface of the shaft, acircular clutch element carried in an opening in the wall of the shaftbeneath the member, free to rotate thereon about its own axis andcapable of being moved radially outwardly to engage a recess in themember, a rotatable actuating element positioned in the hollow shaft andcarrying a part for engaging the clutch element to force it outwardly,said part being capable of passing beneath said clutch element from aninoperative position no one side thereof to an inoperative position onthe other side thereof as the element is rotated, means for rotatingsaid actuating element in opposite directions, synchronizing meansincluding cooperating friction surfaces carried by the shaft and therotatable member, and means carried by the actuating element foroperating the synchronizing means, said last named means being operablein both directions of rotation of the actuating element to cause thesynchronizing means to function prior to movement of the clutch elementinto operative position.

7. In a transmission mechanism, a hollow shaft, a member rotatablethereon and provided with recesses and a friction surface adjacent theexternal surface of the shaft, radially movable clutch elements carriedin openings in the wall of the shaft and adapted to be moved outwardlyto engage said recesses and lock the shaft and member together, amovable friction member carried by the shaft and adapted to be movedinto engagement with the friction surface of the rotatable member, anactuating member positioned in the hollow shaft for relative rotationthereto, means carried by said actuating member for first actuating themovable friction member and then the clutch element as the actuatingmember is rotated, and means for rotating the actuating member.

8. In a transmission mechanism, a hollow shaft, a member rotatablethereon and provided with recesses and a friction surface adjacent theexternal surface of the shaft, radially movable clutch elements carriedin openings in the wall of the shaft and adapted to be moved outwardlyto engage said recesses and lock the shaft and member together, amovable friction member carried by the shaft and adapted to be movedinto engagement with the friction surface of the rotatable member, anactuating member positioned in the hollow shaft for relative rotationthereto, means on said actuating member for engaging and moving theclutch elements out- Wardly into the recesses when the actuating memberis rotated, a spring-operated plunger carried by the actuating memberfor engaging and operating the movable friction member, said springplunger and the means for moving the clutch elements being so relatedthat the former will be caused to be operative prior to the latter whenthe actuating member is rotated, and means for rotating said actuatingmember.

9. In a transmission mechanism, a hollow shaft, a member rotatablethereon and provided with recesses and a friction surface adjacent theexternal surface of the shaft, radially movable clutch elements carriedin openings in the wall of the shaft and adapted to be moved outwardlyto engage said recesses and lock the shaft and member together, amovable friction member carried by the shaft and adapted to be movedinto engagement with the friction surface of the rotatable member, anactuating member positioned in the hollow shaft for relative rotationthereto, and independent means carried by said actuating member and sorelated to each other and the clutch elements and friction member thatthe friction member will be operated prior to the clutch elements whenthe actuating member is rotated in one direction to cause the clutchelements to be operative and then inoperative or in the return directionof rotation to also cause the clutch elements to be operative and theninoperative.

10. In a transmission mechanism, a hollow driven member, two drivingmembers mounted thereon and each provided with recesses, radiallymovable clutch elements carried by the driven member for engaging therecesses and locking the driving members to the driven member, arotatable actuating member positioned in the hollow driven member, andmeans carried by the actuating member for causing certain of the clutchelements to engage recesses in one driving member when the saidactuating member is rotated in one direction from a predeterminedposition and other means carried by the actuating mem-' ber for causingcertain other of the clutch elements to engage recesses in the otherdriving member when the actuating member is rotated in the oppositedirection from said predetermined position.

11. In a transmission mechanism, a hollow driven member, two drivingmembers mountedthereon and each provided with recesses, radially movableclutch elements carried by the driven member for engaging the recessesand lockin the driving members to the driven member, a rotatableactuating'member positioned in the hollow driven member, meansassociated with each driving member and the driven member forfrictionally connecting the former to the latter, and means carried bythe actuating member for successively operating the friction member andthe clutch elements associated with one driving member when saidactuating member is rotated in one direction from a predeterminedposition and for successively operating the friction member and theclutch elements associated with the other driving member when saidactuating member is rotated in the opposite direction from saidpredetermined position.

GLENN T. RANDOL.

